[Resistance of Listeria monocytogenes to cefotaxime and ceftriaxone combined with an aminoside].

The in vitro antibacterial activity of cefotaxime and ceftriaxone-aminoglycoside combinations was studied against 20 clinical isolates of Listeria monocytogenes, and compared with the activity of the antibiotics alone. Minimal bacteriostatic and bactericidal concentrations (MBCs) as well as killing curves were determined using different parameters. In all cases, the MBCs of gentamicin and netilmicin were shown to be lowered by addition of CTX or CTR. Using Mueller-Hinton broth the values of MBCs obtained were achievable in the CSF. However, the clinical bearing of these results remained to be discussed.